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Montana Field Guide

Montana Field Guides

A Freshwater Sponge - Heteromeyenia baileyi

Potential Species of Concern
Native Species

Global Rank: G5
State Rank: S1S3
(see State Rank Reason below)

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State Rank Reason (see State Rank above)
This Freshwater Sponge is currently ranked a "S1S3" Potential Species of Concern in MT and is potentially at risk because of limited and/or potentially declining population numbers, range and/or habitat, making it vulnerable. Known occurrences in Montana are limited to one lake in Lincoln County.
General Description
[From Ricciardi and Reiswig 1993] Based on eastern Canadian specimens: sponge green (due to symbiotic algae) or pale yellow, thin, encrusting, with hispid surface. Megasclereres amphioxea, smooth or sparsely spined; spines minute, blunt, rosettelike; megasclere length 216-320 microns, width 5-13 microns. Microscleres amphioxea, extensively covered with spines; spines increasing in length toward center of spicule where they are perpendicular and with knobbed tips; maximum spine length greater than maximum spicule width; microsclere length 53-83 microns, width (excluding spines) 1-4 microns. Gemmules yellow, spherical, generally < 500 microns diameter; foramen slightly raised, lacking terminal cirri. Gemmoscleres of two intergrading classes: 1) short birotulates with flat, serrated rotules; spicule length 38-51 microns, shaft width 3-7 microns, rotules diameter 13-22 microns; 2) long birotulates with rotules composed of long recurved hooks, giving rotule an umbrella-like appearance; hooks often with knobbed tips; spicule length 49-86 microns, shaft width 3-7 microns, rotule diameter 18-28 microns.

Diagnostic Characteristics
Readily separated from H. tubisperma by foraminal structure of gemmule: H. baileyi lacks an extended foraminal tube, the umbrella-like rotules on the longer gemmosclere are fairly distinctive, the microscleres are generally shorter and less densely spined, spines on microsclere generally perpendicular throughout (instead of being recurved at ends and becoming perpendicular and larger near center of spicule) (Ricciardi and Reiswig 1993).

Range Comments
Distribution data for US and Canada is known to be incomplete or has not been reviewed for this taxon. Records in eastern Canada from Quebec, New Brunswick, Nova Scotia (Ricciardi and Reiswig 1993). Reported in Montana from one locality in Lincoln County.

Observations in Montana Natural Heritage Program Database
Number of Observations: 1

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Relative Density



(Observations spanning multiple months or years are excluded from time charts)


Encrusts stones and vegetation in lakes and sluggish streams in Laurentian region of eastern Canada. Reported from water quality conditions with pH 5.9-8.2, temperature 15-26 C (Ricciardi and Reiswig 1993). At Lincoln Co., Montana site encrusts sediments growing on root mass, in water quality conditions of pH = 6.0.

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Citation for data on this website:
A Freshwater Sponge — Heteromeyenia baileyi.  Montana Field Guide.  .  Retrieved on , from